The present invention relates to a machine to facilitate sod destruction and decomposition, and a method of using the machine. The machine comprises multiple colters positioned to cut and crush sod horizontal roots and rhizomes while leaving vertical net roots uncut. The method of using the machine comprises making multiple passes over a sod field in a criss-crossing pattern.
Destruction of sod is a difficult soil working process that is desirable when planting certain row crops and root crops. Row crops require proper tilth of a seed-bed, which cannot be obtained when large clumps of sod are present. Root crops, such as potatoes, cannot be separated from large clumps of sod during harvest. Therefore, adequate destruction of sod for row and root crops requires that the sod be reduced into small, untangled segments that allows planting and harvesting of crops. Such a result could be accomplished if a machine were capable of cutting horizontal roots and rhizomes, while leaving vertical roots uncut to hold the sod in position for the cutting of the horizontal roots.
Many machines have been developed for working soil including plows, tillers, disks, cultivators, and sod cutters. These machines are generally designed to cut both horizontal and vertical roots of sod or stubble to accomplish the desired soil working process. Such machines tend to leave large clumps of sod in a field, which significantly increases the time necessary for proper sod destruction and decomposition. Until the discovery of the instant invention, no soil working machine or apparatus has been developed to facilitate the destruction and decomposition of sod by cutting horizontal roots and rhizomes while leaving vertical net roots uncut.
Machines to cut and roll sod for turf installation are well known. Such machines are designed primarily to cut all vertical roots of an area of sod and secondarily to cut a limited perimeter portion of vertical roots of the sod. Because the horizontal roots are only cut around the perimeter of the area of sod, the sod can be rolled up as a single piece and then transported to another location for turf installation. An example of such a sod cutting and rolling machine is disclosed in U.S. Pat. No. 6,135,211, which issued Oct. 24, 2000 to Schroeder. The sod cutting machine of Schroeder includes two side-cutting blades, and a lower cutting blade. One side-cutting blade is mounted on each side of the lower cutting blade. The side-cutting blades are positioned to cut the horizontal roots on each side of a strip of sod, while the lower cutting blade is positioned to cut the vertical roots below the strip of sod. Although this machine is effective in removing sod from a field, it does not facilitate sod destruction and decomposition within a field. The purpose of Schroeder""s machine is to preserve the sod for re-installation, rather than to destroy and decompose the sod within the field.
Several prior art machines have been developed to facilitate the destruction and decomposition of sod. For example, U.S. Pat. No. 1,040,890, which issued on Oct. 8, 1912 to Cook, discloses a motor plow to slice or cut sod and plow the soil below the sod. Cook""s invention shows two gangs of rotary disks arranged at the front and rear of a frame, and one or more plows positioned between the gangs of disks. The plows can be raised and lowered to control their operation. The angles of the disks with respect to the line of movement of the machine can be varied to increase and decrease the cultivation action of the disks. When the planes of the disks are parallel to the line of movement, the disks operate only as wheels with no cultivating action. A significant disadvantage of this machine is that the angle of the disks needed to cultivate the sod result in cutting the vertical roots of the sod while leaving a significant amount of horizontal roots and rhizomes fully intact. By cutting vertical roots and leaving horizontal roots intact, this machine will leave rather large clumps of sod loose in a field. These large clumps of sod will take a significant period of time to decompose. Additionally, once the vertical roots have been cut and a clump is loosened from the soil, further destruction of that clump by additional passes with the machine is curtailed as the disks will tend to merely push the clump aside rather than cut the remaining horizontal roots of the clump. Therefore, it would be advantageous to develop a machine that cuts primarily the horizontal roots of sod, while leaving the vertical roots uncut to hold the sod in position during the cutting of the horizontal roots.
U.S. Pat. No. 922,178, which issued on May 18, 1909 to Nelson and U.S. Pat. No. 1,258,930, which issued on Mar. 12, 1918 to Nesterud disclose several quack grass destroyer machines which cut sod into strips, lift the strips of sod from the ground, remove soil from sod roots, and then return the sod to the ground for decomposition. Both of these machines require rather bulky and complex mechanisms to lift the strips of sod from the ground and remove the soil from the roots. Therefore, it would be advantageous if a machine could be developed that would facilitate the destruction of sod without requiring a complex mechanism to lift the sod from the ground and remove the soil from the roots.
A principal object of the present invention is to provide an improved machine to facilitate the destruction and decomposition of sod within a field.
Another object of the present invention is to provide a machine to facilitate the destruction and decomposition of sod within a field without requiring temporary removal of the sod from the field for sod destruction.
Another object of the present invention is to provide a machine to facilitate the destruction and decomposition of sod within a field by cutting and crushing primarily horizontal roots and rhizomes while leaving vertical net roots uncut.
The above described objectives are achieved using an apparatus comprising a frame, and at least a first and second gang of colters mounted to the frame. The second gang of colters is mounted behind the first gang of colters in a staggered relationship with respect to the first gang of colters. The cutting edge of each individual colter is positioned in a direction parallel to the direction of travel of the apparatus, such that as the apparatus moves in a forward direction over a field of sod, the horizontal roots of the sod will be cut in a straight line parallel to the direction of forward movement. The precise positioning of the cutting edges of the colters allows the apparatus to cut primarily horizontal roots and rhizomes without cutting vertical roots.
One embodiment of the apparatus of the instant invention includes wheels mounted to the frame, the height of the wheels can be adjustable to control the depth that the colters cut into the sod. Additionally, the wheels can be used to raise the colters entirely above the ground to allow the apparatus to be transported easily from field to field.
In another embodiment, the spacing between individual colters in a given gang can be adjusted by using spacers of varying widths. Additionally, each gang of colters can be adjusted horizontally from side to side of the apparatus. The horizontal adjustment allows for the repositioning of the colter gangs to maintain the staggered relationship of the gangs when spacer widths are modified.
The apparatus must be of sufficient weight to allow the colters to penetrate the roots of the sod. Weight blocks can be added to the frame if additional weight is required.
In operation, the apparatus moves in a forward, relatively straight, first direction across a field of sod. As the first gang of colters is pulled across the sod, it will cut the horizontal roots and rhizomes of the sod such that strips of sod are formed. The second gang of colters is pulled across the strips of sod; due to the staggered relationship of the second gang of colters with respect to the first gang of colters, the strips of sod are cut into increasingly smaller strips of sod. The staggered relationship of the colter gangs allows the sod to be cut into widths substantially narrower than that which may be achieved by a single gang of colters. As many additional gangs of colters can be positioned behind the second gang of colters as needed to obtain a desired strip width. Once a first pass over a field of sod is made, the apparatus can be pulled over the same field in a direction relatively perpendicular to the first direction. This second pass allows the strips of sod to be cut into small segments. Because the colters are positioned to only cut horizontal roots and rhizomes, the intact vertical roots will hold the sod in position for the second gang of colters, any additional gangs of colters, as well as additional passes with the machine.
As the colters are pulled across a field of sod, the action of cutting provides a secondary advantage of crushing the horizontal roots and rhizomes of the sod near the incision point of each colter. This crushing action loosens horizontal root hairs from the soil, which increases the destruction and decomposition of the sod. This crushing action is generally isolated to a relatively small area near the incision point of a colter. As a result the crushing action will only provide a considerable advantage when a field of sod is cut using the apparatus of the instant invention which cuts the sod into narrow strips. When a strip of sod is cut too wide, the crushing action of the colters will not sufficiently loosen the horizontal roots from the soil across the entire width of the strip of sod.
The foregoing and other objects are intended to be illustrative of the invention and are not meant in a limiting sense. Many possible embodiments of the invention may be made and will be readily evident upon a study of the following specification and accompanying drawings comprising a part thereof. Various features and subcombinations of invention may be employed without reference to other features and subcombinations. Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention.